Galvanic cell

                           Oxidation
is defined as

• the addition of oxygen to a substance
• the loss of hydrogen from a substance
• the process of electron loss from a substance
• an increase in the oxidation number of a substance

                         Reduction

is define as

• the loss of oxygen from a substance
• the addition of hydrogen to a substance
• the process of electron gain in a substance
• a decrease in oxidation number of a substance

                     Redox reaction


are reaction involving oxidation and reduction